Final answer:
Technician A is correct. A Normally Closed Contact (NCC) can operate a component while the relay is off. Technician B is also correct. A NCC may exist but not be used in some circuits.
Step-by-step explanation:
Technician A is correct. A Normally Closed Contact (NCC) is a type of switch that is closed (allows current to flow) in its normal or unenergized state. When the relay is off, the NCC is closed and allows the component to operate. When the relay is energized, the NCC opens and interrupts the current flow to the component.
Technician B is also correct. In some circuits, a NCC may exist but not be used. This means that the NCC is present in the circuit, but it is not connected to any component or used to control any operation.